Soil Sampling For

Home Landscape and Garden

Developed by:

Dr. Teri Hamlin

Georgia Department of Education

Purpose

Determining the fertility level of a soil through a soil test is the first step in planning a sound lime and fertilization program for the home landscape and garden.

Purpose

A soil test provides the means of monitoring the soil so deficiencies, excesses and imbalances can be avoided.

Many Georgia soils are low in pH and one or more of the essential plant nutrients.

Maintain Soil Fertility

Soil testing is any chemical or physical measurement that is done on soil.

It is indispensable in establishing and maintaining a Soil Fertility Program.

The Soil Testing Laboratory

Soil tests such as those conducted by the University of Georgia Soil Testing and Plant Analysis Laboratory will help you develop and maintain a more productive soil by providing information about the fertility status of your soil.

Lime & Fertilizer Recommendations

Information from a soil test will help you select the proper liming and fertilization program to obtain optimal growth of lawn, garden and ornamental plants.

Procedure

One of the most important steps in soil testing is collecting the sample.

Soil test results can be no better than the sample submitted to the laboratory for analysis.

A soil sample weighing about 1 pound is used to represent thousands of pounds of soil in the landscape or garden.

A Good Soil Sample Should Be Representative of the Area

Procedure

Take soil from a minimum of 10 random locations (x) in the sampled area and mix together in a clean bucket.

For trees and shrubs, take soil from six to eight spots around the drip line of the plants and mix.

Do Not Contaminate the Sample

Use clean sampling tools and containers. Never use tools or containers that have been

used for mixing or applying fertilizer or limestone. A small amount of residue on containers can cause serious contamination of the sample.

Sample to the Proper Depth

Remove any surface litter such as turf thatch or mulch.

For lawns, sample to a depth of 4 inches.

For gardens, ornamentals and fruit trees, sample to a depth of 6 inches.

Tools

Use a trowel or sampling tube to collect soil samples.

Tools

To use a trowel or spade, push the tool to the desired depth into the soil.

Then push the handle forward, with the trowel or spade still in the soil, to make a wide opening.

Cut a thin slice from the side of the opening that is of uniform thickness -- about ¼ inch thick and 2 inches wide, extending from the top of the ground to the depth of the cut

Soil Samples Should Be Carefully Mixed and Packaged

All cores taken for a given sample should be collected in a clean bucket and thoroughly mixed.

Soil Sample Bag

Fill the soil sample bag to the indicated line with the mixed soil.

Supply all the information asked for on the soil sample bag.

List your Name and Address, Plant to Be Grown, Sample Number

Soil Sample Bag

On the bag, indicate tests desired by checking the proper box.

For lawns, gardens and shrubs, a routine test will suffice.

Laboratory Tests and Fees

Routine Tests: pH, L.R., Soil Test P, K, Ca, Mg, Mn and Zn

Micronutrient Tests: Boron (B)

Other Tests: Organic Matter Content, Soluble Salts, Nitrate Content

Commercial Greenhouse or Nursery Soil Test: pH, Soluble Salts, NH4, NO3, P, K, Ca, Mg

Routine Test for Lawns & Gardens

Routine Test: pH, Lime Requirement (L.R.), Phosphorus (P), Potassium (K), Calcium (Ca), Magnesium (Mg), Manganese (Mn), Zinc (Zn)

Routinely recommended for all commercial field and vegetable crops as well as home lawns and gardens

County Extension Office

Samples should be dropped off at your county extension office for mailing to the laboratory.

Soil Analysis Lab

Sample Receiving

The soil samples are organized in a set of 100 and are logged in with lab numbers in the order they are received.

Soil Analysis Lab

Preparing the Samples for Analysis - A "blank" and two "check" samples are placed in each set for quality control.

Soil Analysis Lab

Drying Racks – The samples are dried at

room temperature with a fan or at a low temperature (if they are very wet) on drying racks

Soil Analysis Lab

Grinding the Samples –

With one pass through a "grinder" each sample is broken up and sieved through a 10-mesh screen

Soil Analysis Lab

Checking the Forms – The order of the samples is double checked

against the sample submission forms in each set.

The forms are then taken to the data processor who enters the name and address information along with the lab numbers into the database.

After the samples are analyzed, the data is electronically merged with the other information from the forms to generate the final soil test report.

Report

Report Format – The report for each sample

includes results, calculations, and recommendations and comments for up to four crops or landscape areas.

Recommendations can be obtained in lbs/acre or lbs/100 or 1000 square feet by using different crop codes.

When and How Often Should Soils Be Tested?

Soils can be tested any time during the year; however, be sure to sample well in advance of planting or spring green-up.

Generally, fall is the most desirable time to sample soils, because landscapes and gardens are usually dry and easily accessible.

When and How Often Should Soils Be Tested?

Soils should be dry enough to till when sampling.

Once medium or high fertility levels are established: – lawn and ornamental areas only need to be

sampled every two to three years– vegetable gardens should be sampled every one

to two years

Record Keeping

Keep previous soil test results for each area and refer to them when you plan limestone and fertilizer applications.

Periodic soil sampling of each area will help determine whether you are following a soil buildup or soil depletion program.

If a sound soil testing program is not followed, a deficiency or an excess in fertilization rates can result.

Final Results

By sampling and determining the fertility level of a soil

Applying proper amounts of lime and fertilization

Result in a healthy home landscape and garden